Glaysche

Eurobricks Vassals
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About Glaysche

  • Birthday 01/12/1975

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    Technic
  • Which LEGO set did you recently purchase or build?
    42043

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    Male
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    San Francisco

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    United States

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  1. My dream set on the survey is the Perseverance Mars rover as a flagship. There is so much you could do with that.
  2. Thank you very much! One other thing I thought was interesting: This is the main vertical arm. The basic cross section is 5x5 studs. I needed a motor in it so I was able to fit an L motor inside. The motor is actually part of the structure providing strength. There are 4 12t gears driving the 2 60t turntables. This made the gear train much more robust. When I only had 1 12t gear per turntable, it sometimes would skip. The 28t gears were the largest I could fit in that spot which helped make the rest of the gear train lower torque. I used this same technique for all the high-stress joints. The highest stress joint on the bottom has the most complicated gear train. It has 16:20, 12:36, 12:20, 8:28, 12:60 gearing packed in the base to allow the XL motor to drive it.
  3. I have made a lot of progress on this robotic arm. At first, I did a bunch of optimizing of various structures, made it look a little better with better colors, and a few other things. I ended up with this: This is still basically the same as before, just incrementally improved. The big problem here is that the final couple parts of the robotic arm are too heavy for the large turntable and the way the construction works is very cumbersome to take apart. In order to get the top part of the arm apart, it needs to be taken apart into many small pieces -- not very modular. This was the best I was able to build with 100% pure Lego pieces. The next step was to use a 3D printed part designed by @efferman that allows transmitting 3 functions through a turntable: This can be found at https://www.shapeways.com/product/BGBRHWES5/three-functions-through-turntable?optionId=138357654. This was a revolution. I was able to make the end of the arm much smaller and lighter. It works much better and is now a very modular build. Here's what the new one looks like: The motors have moved to the back of the arm for good balance. This allowed me to move the hub down onto the arm which reduces stress on the bottom joint. It also is very modular. The red pins and parts typically indicate the parts to remove to take it apart into big pieces: Every joint now works well in my testing. Software is now a challenge. The hubs pictured here are the Spike Prime hubs. I'm actually using them with the Robot Inventor firmware for my tests. RI does not allow controlling multiple hubs simultaneously which has some work-arounds. It also has some incompatibilities with the L and XL motors I used -- you can't read the position on those. I could convert to use just standard technic hubs but the form factor is not nearly as nice. I'm still figuring out my options here. I have an email into Lego support about the incompatibility problems with the L and XL motors. We will see what they say. Retrospective Building this had different challenges than I thought it would when I started. I thought the big challenge would be designing the gear trains -- and they are complicated. I use 6 different differentials and precise gear ratios to eliminate coupling of functions sent through turntables. The most complicated is the top unit: This gearing allows rotating the turntable without unwanted movement in any of the other axes. The real challenge was the limitations in the strength and rigidity of the lego parts themselves. Every time I was able to improve bracing, make it more rigid, or have better form locking, everything worked better. I went through many iterations coming up with better structures. There are still things that are not as good as I would like but I think it is pretty good right now. I also found wire routing challenging. A lot of work went into routing wires well which you can see in the above picture and a couple others: That last picture also shows a color sensor I am using for calibration. I haven't been able to build a full calibration routine because of the software limitations I mentioned earlier. Another thing that has been challenging that I didn't suspect was something I'll call "color engineering". I want the colors to be clean and look nice. I don't want to see blue pins or axle pins anywhere. I ended up re-engineering different parts to eliminate the blue axle pins. I couldn't eliminate all of them so I did end up buying some of the expensive black axle pins on Bricklink. When I first built this, almost all parts were common and purchasable on Brick and Pieces but to get the colors right, I needed to buy rare parts. Some of the lime green parts are hard to find. Anyway, I wouldn't call this project done but I think most of the work now will be software related so if I end up posting about it, I will probably move it to the Mindstorms forum. I posted this here because the Mindstorms components are pretty much incidental right now. Most of my development was done with Technic hubs. It was a super fun project. I would love to hear any comments and suggestions on improvements.
  4. I would like to hear some basics about the part development process. How was it decided to build these specific parts? What were the biggest challenges in designing them? What were the tradeoffs in the design? Any regrets about the final design? Anything you would do differently next time?
  5. Glaysche

    latest lego quality standards

    My collection is not as old as some here but I have not seen parts breaking nearly as much as is being reported here. I have a couple ideas. Maybe different manufacturing plants are producing different quality parts? Some people (or even whole regions of the world) are unlucky and getting poorer quality parts? Another thought I have is that exposure to sunlight might cause the plastic to get more brittle. If models are on the shelf in the sun, could that cause the parts to degrade and break more often?
  6. Glaysche

    [MOC] Christmas Tree (of Doom)

    This is hilarious. I love it.
  7. Glaysche

    Mindstorms General Discussion

    To follow up on my own post, this is what I am working on. I’ve done most of my testing with Powered Up hubs and app. The Spike Prime / RI hubs are much nicer and I would vastly prefer using those. This robotic arm has a large angular motor for rotation which seems to work fine. The XL motor is on the bottom tilt axis. 5 L motors control the other axes. Oh, I should mention the Spike Prime hubs have 51515 firmware and I’m using the 51515 iPad app. I’m using these because I think the yellow looks better than the teal in this application. I suspect the RI hub will have the same behavior.
  8. Glaysche

    Mindstorms General Discussion

    I did a test of Powered Up L and XL motors on the 51515. The basic functions work like start and stop motor. Some more advanced functions seem to work like “move to relative position” and “move 2 rotations”. Reading the current position or relative position seems to always return zero. This seems strange that encoder would work for some things but not others. Anyone else see this? I just reported to Lego support but I’m sure a response will take a while. Have any of you reported this?
  9. I have tried to build my MOCs with only parts available from Lego Bricks and Pieces. In fact, I often have used the newest parts available like the 15x11 frame or the new differential. It’s nice to see what the new parts can do. That being said, I will buy rare parts to get a specific color, especially on the pins and axles. That way, if someone else doesn’t want to buy the rare parts, they can can use a common part in a different color.
  10. Glaysche

    [RUMORS] Flagship - CAT D11T

    An option that would be pretty nice would be if they included a 51515 hub instead of two Technic hubs. That would allow 6 motors with a single hub and be rechargeable. To follow the pattern before of Mindstorms components going to technic, they would probably recolor the hub to be LBG/DBG just like the large angular motor that went into 42114. I suspect it would be a relatively simple software change to make the 51515 hub work with the PoweredUp and Control+ apps.
  11. Glaysche

    Technic General Discussion

    If you look around, it seems most other themes are largely sold out as well. (I'm also in the USA.) Maybe they are focusing all manufacturing capacity on the 2021 sets?
  12. Glaysche

    [MOC] Lego Pneumatic Steam Locomotive

    This MOC is just stunningly good. This is one of my favorite things I have ever seen in Lego.
  13. Glaysche

    2 speed automatic car - Ramp Test

    I have loved following this series. Applying theory to lego mechanics is very interesting.
  14. Glaysche

    [WIP] Telescoping boom excavator

    I've been working on a robotic arm that went through many of these same challenges. I actually tried a 60t turntable with 1L worm gear, 56t turntable with 2L worm gear, and a variety of other things. I was not happy with any of the solutions. What I eventually ended up doing was to have 2 12t gears driving a 60t turntable. This ended up reliably rotating in both directions and was a pretty reasonable amount of structure needed to make it all work. Here are some pics: This is the robotic arm. The joint of interest here is the rotating joint at the top. Zooming in on that, I have two 12t gears driving the turntable: Here's a pic with the arm removed: These 2 12t gears are attached to 28t gears which are driven by an 8t gear seen at the top middle. This localizes all the high torque to just those two axles and the rest of the gear train is relatively low torque and easier to deal with. These two axles needed really good axle support but once that was built, it worked pretty well.
  15. I think the one you are looking for may be the second video on this Akiyuki blog post. https://akiyuki.jp/en/1548